The present invention relates to a device for vertically adjusting headrests, especially to a device for vertically adjusting chair headrests and having a sliding member, a fixed member and a button set.
Nowadays people focus on comfort and functions of chairs. Thus armrests, waist support or a headrest of the chair are added with certain devices to become multifunctional. For example, the armrest is able to be moved in forward-and-backward directions, or leftward-and-rightward directions. The waist support or the headrest can be adjusted vertically.
However, a larger and direct force is required to be applied to the conventional adjustment device for vertically adjusting the headrest. The force applied results in loud noise. The larger force required would cause inconvenience to the elderly, women and children.
Moreover, refer to TW105109443, CN201620252226.5, U.S. Ser. No. 15/149,893, and DE202016101985.0, these prior arts have revealed the button operation and the use of damper gears. Yet these are applied to the armrest of the chair, not to the armrest. The arrangement and action of both moving parts and fixing parts of the armrest and those of the headrest are quite different. The inventor of the present invention also has invented certain prior arts related to the headrest of the chair such as CN201610844760.4, U.S. Ser. No. 15/292,649, etc. But the technical and structural features of these prior arts are different from those of the present invention. Thus there is room for improvement and there is a need to provide a novel device for vertically adjusting the headrest of the chair.